> For the complete documentation index, see [llms.txt](https://docs.revrobotics.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.revrobotics.com/duo-control/menu/adding-more-motors/adding-an-expansion-hub.md).
# Adding an Expansion Hub
If you want to use more than 4 motors or 6 servos, you can add an Expansion Hub to your robot. An Expansion Hub ([REV-31-1153](https://www.revrobotics.com/rev-31-1153/)) can be added to a Control Hub ([REV-31-1595](https://www.revrobotics.com/rev-31-1595/)) or another Expansion Hub. The Expansion Hub has all of the same ports as the Control Hub but without the wireless capability.
### Control Hub vs Expansion Hub in FIRST
| **FIRST Tech Challenge** | **FIRST Global** |
| -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| FIRST Tech Challenge teams may use one (1) Control Hub and may add one (1) Expansion Hub starting in the 2020-2021 season. Read the official FTC Game Manuals for complete game rules. | FIRST Global teams must use one (1) Control Hub and may add one (1) Expansion Hub to their robot. Read the official FIRST Global manual for complete game rules. |
{% hint style="warning" %}
If you are using a configuration file from a 5.5 or earlier version of the Robot Controller Application, you will need to create a new configuration file.
{% endhint %}
### Adding an Expansion Hub to your Robot
| Step | Image |
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------- |
| Use the XT Extension Cable to connect power between the Control Hub and the Expansion Hub.
Use a 3-pin JST PH cable to connect the RS485 port on the Control Hub to the Expansion Hub.
|  |
| From the Driver Station choose “Configure Robot” |  |
| Select “New” in the top left hand corner. |  |
| Select “Control Hub Portal”
Note: This will show an Expansion Hub Portal if using an Android Device as a Robot Controller
|  |
| Now you have two Hubs to choose from. Either the Control Hub or the Expansion Hub.
“Expansion Hub 2” is the connected Expansion Hub that is communicating over RS485.
Configure and program as necessary. Please see the Configuration section of for an overview of configuration.
Note: If using an Android Device as a Robot Controller there will be two Expansion Hubs located here. The Expansion Hub Address may need to change so they do not conflict.
|  |